Ginkgo Biloba Doesn't Slow Mental Decline
Popular Supplement Fails to Slow Mental Decline in 6-Year Study
Dec. 29, 2009 - The hot-selling herbal supplement ginkgo biloba doesn't slow
age-related mental decline, a six-year clinical study shows.
The study has already shown that ginkgo does not prevent dementia or Alzheimer's disease in the elderly.
Now study leader Steven T. DeKosky, MD, and colleagues have sifted through
the data to look for some sign that ginkgo might slow mental decline in
healthy, aging individuals -- or, perhaps, in those already showing the first
signs of cognitive impairment.
No such sign was found.
"Compared with placebo, the use of Ginkgo biloba, 120 mg twice daily,
did not result in less cognitive decline in older adults with normal cognition
or with mild cognitive impairment," the researchers conclude.
The problem wasn't potency. The study used the standardized ginkgo extract
from Schwabe Pharmaceuticals that is regulated and sold as a medication in
And the problem wasn't rigorous testing. Twice a year, the 72- to
96-year-old study participants received a battery of tests that measured
various aspects of mental function, including memory, attention, visuospatial
abilities, language, and executive function.
Regardless of which mental function was measured, the tests show gingko
doesn't help slow cognitive decline.
The findings echo those of a 2009 Cochrane Review of ginkgo studies that
identified no cognitive benefit from the supplement.
The Council for Responsible Nutrition, a group representing the supplement
industry, suggests that the DeKosky study "should not be viewed as the final
work" on ginkgo.
In a written statement, Douglas MacKay, ND, CRN vice president for
scientific and regulatory affairs, notes that cognitive decline has many causes
and that neither ginkgo nor any other single treatment is a magic bullet.
"As a former practicing licensed naturopathic doctor, I have had the benefit
of working with patients and have seen first-hand how Ginkgo biloba can
be effective in improving cognitive function," MacKay says. "I would continue
to recommend Ginkgo biloba to older adults as a safe, effective option
for supporting cognitive health and would encourage consumers to talk to their
own healthcare professional about what is right for them."
DeKosky and colleagues report their findings in the Dec. 23/30 issue of
The Journal of the American Medical Association.